Section C. Dairy Chemistry

Abstract

THIS review records the progress of dairy chemistry for the period extending from the end of that dealt with in a previous review(l) to August 1935; the subject will be dealt with under the same broad subdivisions as in the previous review. No new journals describing researches into dairy chemistry have appeared; a second edition (1935) of Fundamentals of Dairy Science by Associates of L. A. Rogers (Reinhold Publishing Corporation, New York) has been published. In the progress of dairy chemistry during the last two years, the subjects which have aroused greatest interest are: the composition and autoxidation of butterfat; the composition of casein; the physical chemistry of milk and its products; and the technology of butter and cheese manufacture. I. THE COMPOSITION OF MILK (a) THE AVERAGE COMPOSITION OF MILK In the following table are collected additional data on the average composition of milk: Investigators Golding et al. <a>* Goldinget al.m] Cornalbao) RoginaM) * Calculated from the results for morning samples taken on one day per week. •f Calculated from the results for morning and evening samples taken every day for roughly 2 years. In addition to the average proximate composition of milk given above, Cornalba(3) found an average of 4-8 per cent, of lactose, 2-8 per cent, of casein, 0-46 per cent, of albumin and 0-8 per cent, of ash. Rogina(4) found the fat content of his 379 samples to vary from 2-71 to 4-81 per cent., the standard deviation from the mean being 0-95. Cole and Johansson(5) found that the composition of the milk of Aberdeen-Angus cows compared favourably with that of the milk of the Channel Island breeds, e.g. 4-06 per cent, fat and 3-56 per cent, protein, both decreasing slightly with advancing age of the cow. There was also a correspondingly high lactose content. The cases of adulteration of milk, reported by the Ministry of Health (6) annually, account for roughly 7-5 per cent, of the samples examined by public analysts. The figures are: 1932-33: 5307 out of 72,940 samples (7-3 per cent.); 1933-34: 5760 out of 74,545 samples (7-7 per cent.).

Verwertung von Betain als N‐Quelle bei niedriger Proteinversorgung von Hammeln

“…wachsenen Schaf als indifferente N-Verbindung, die zur Proteinversorgung nicht beitragt. Aus spateren Untersuchungen an Rindern und Schafen (DAVIES 1936;NEILL et al 1978;MITCHELL et al 1979) geht hervor, daB Pansenbakterien aus Betain und auch aus Cholin rasch Trirnethylamin (TMA) abspalten, das teilweise absorbiert und schlieglich vorwiegend als Trirnethylarnin-N-oxid (TMAO) iiber die Nieren ausgeschieden wird. Im vorliegenden Differenzversuch mit Hammeln sollte daher gepriift werden, wie sich die Zulage von Betain zu einer Basalration rnit niedrigem Rohproteingehalt auf Nahrstoffverdaulichkeit, renale N-Fraktionen und N-Bilanz auswirkt.…”

The stability of vegetable oils IV. Flavor reversion in soybean oil

“…a This compound is associated with the decomposition products of lecithin, choline, etc.. cf. Davies(17).…”

Section C. Dairy Chemistry

“…THIS review records the progress of dairy chemistry during the period extending from the end of that dealt with in a previous review (1) to August 1937; the subject will be dealt with under the same broad subdivisions as in the previous review.…”